Maui Coral Reef Holds Secrets Of The Past — And The Future

New research into a 253-year-old coral sample from Olowalu provides a first-of-its-kind glimpse into the environmental history of Maui.Scientists who studied the two-century-old core found that the reef’s growth, or lack thereof, closely mirrored what was happening on land. The period they examined, 1760 to 2013, covers the precolonial era, the rise and fall of the sugar-plantation economy and Maui’s development as a tourist mecca.Their findings, published in the September issue of the scientific journal “Coral Reefs,” offer the “first long-term baseline for understanding ridge-to-reef connectivity on Maui,” according to the U.S. Geological Survey, which originally collected the core in 2013.The scientists also were able to pinpoint for the first timethat the reef’s growth rate began a steep decline in the late 1960s when the plantation economy boomed.“There’s been several studies showing a connection between historical sugarcane production and poor water quality,” said Andrea Kealoha, a study co-author.

“But nobody has been able to connect that to the decline of reef health.”The new study is significant given Olowalu’s international reputation as a super reef, a mother reef and even a turtle reef, basically a marine rock star for its unique qualities and important contributions to ocean health.By revealing how land-use patterns affected the reef, the study provides not only a window into the past but a roadmap for land managers making ridge-to-shore decisions.Learning From The Reef’s PastSam Kekuewa of Hawaii Sea Grant College Program led the research team, which included scientists from University of Hawaiʻi at Manoa, School of Ocean and Earth Science and Technology, and the U.S. Geological Survey.After the USGS originally collected the 6-foot-long coral core in 2013, the federal agency conducted some initial analysis, but it wasn’t until Kekuewa came along in 2024 that in-depth research on the core began.Kekuewa, who said he grew up amid the Hawaiian diaspora of the San Francisco Bay Area, is a chemical oceanographer with a doctorate from Scripps Institution of Oceanography. After graduating with his PhD in 2024, Kekuewa knew he wanted to live and work in Hawaiʻi.

He initially came to Maui to work as a postdoctoral fellow with Kealoha, an assistant professor of oceanography at UH Manoa.Previously, he had helped Kealoha research how West Maui’s water qual… Scientists who studied the two-century-old core found that the reef’s growth, or lack thereof, closely mirrored what was happening on land. Their findings, published in the September issue of the scientific journal “Coral Reefs,” offer the “first long-term baseline for understanding ridge-to-reef connectivity on Maui,” according to the U.S.

Geological Survey, which originally collected the core in 2013. The scientists also were able to pinpoint for the first timethat the reef’s growth rate began a steep decline in the late 1960s when the plantation economy boomed. “There’s been several studies showing a connection between historical sugarcane production and poor water quality,” said Andrea Kealoha, a study co-author.

By revealing how land-use patterns affected the reef, the study provides not only a window into the past but a roadmap for land managers making ridge-to-shore decisions. Learning From The Reef’s Past Sam Kekuewa of Hawaii Sea Grant College Program led the research team, which included scientists from University of Hawaiʻi at Manoa, School of Ocean and Earth Science and Technology, and the U.S. After the USGS originally collected the 6-foot-long coral core in 2013, the federal agency conducted some initial analysis, but it wasn’t until Kekuewa came along in 2024 that in-depth research on the core began.

Kekuewa, who said he grew up amid the Hawaiian diaspora of the San Francisco Bay Area, is a chemical oceanographer with a doctorate from Scripps Institution of Oceanography. Previously, he had helped Kealoha research how West Maui’s…